A comprehensive music curriculum is characterized by breadth and depth of musical experience. Curricular breadth involves planning for students' participation in a wide range of musical engagements (singing, playing, composing, improvising, listening, moving, evaluating); exposure to a broad repertoire of works, styles, and genres; and emphasis on the ways that music is organized and constructed through its distinctive elements and forms. Depth of musical understanding comes from pursuing a well-chosen sample of these engagements, music, and elements with regularity and intensity. Through a curriculum that offers both breadth and depth, students become aware of the vast possibilities for lifelong involvement which music affords, and gain the keen satisfaction of knowing some music well. This article begins by addressing key concepts that support a principled foundation for interdisciplinary work in music, and next clarifies distinctions among common terms used to refer to curricular schemes for organizing a connected curriculum. Principles that can be used to guide curricular decisions are provided. The article then explores interdisciplinary work in music from the perspective of (1) the teacher, (2) the learner, (3) the overall curriculum, and (4) approaches and models for generating and organizing interdisciplinary experiences. Whenever possible, it supplements its North American perspective (the US and Canada) with select examples that reflect a more international scope.